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from __future__ import division |
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import os |
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import cv2 |
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import dlib |
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from .eye import Eye |
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from .calibration import Calibration |
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class GazeTracking(object): |
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""" |
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This class tracks the user's gaze. |
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It provides useful information like the position of the eyes |
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and pupils and allows to know if the eyes are open or closed |
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""" |
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def __init__(self): |
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self.frame = None |
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self.eye_left = None |
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self.eye_right = None |
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self.calibration = Calibration() |
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self._face_detector = dlib.get_frontal_face_detector() |
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cwd = os.path.abspath(os.path.dirname(__file__)) |
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model_path = os.path.abspath(os.path.join(cwd, "trained_models/shape_predictor_68_face_landmarks.dat")) |
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self._predictor = dlib.shape_predictor(model_path) |
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@property |
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def pupils_located(self): |
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"""Check that the pupils have been located""" |
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try: |
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int(self.eye_left.pupil.x) |
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int(self.eye_left.pupil.y) |
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int(self.eye_right.pupil.x) |
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int(self.eye_right.pupil.y) |
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return True |
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except Exception: |
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return False |
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def _analyze(self): |
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"""Detects the face and initialize Eye objects""" |
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frame = cv2.cvtColor(self.frame, cv2.COLOR_BGR2GRAY) |
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faces = self._face_detector(frame) |
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try: |
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landmarks = self._predictor(frame, faces[0]) |
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self.eye_left = Eye(frame, landmarks, 0, self.calibration) |
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self.eye_right = Eye(frame, landmarks, 1, self.calibration) |
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except IndexError: |
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self.eye_left = None |
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self.eye_right = None |
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def refresh(self, frame): |
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"""Refreshes the frame and analyzes it. |
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Arguments: |
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frame (numpy.ndarray): The frame to analyze |
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""" |
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self.frame = frame |
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self._analyze() |
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def pupil_left_coords(self): |
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"""Returns the coordinates of the left pupil""" |
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if self.pupils_located: |
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x = self.eye_left.origin[0] + self.eye_left.pupil.x |
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y = self.eye_left.origin[1] + self.eye_left.pupil.y |
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return (x, y) |
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def pupil_right_coords(self): |
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"""Returns the coordinates of the right pupil""" |
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if self.pupils_located: |
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x = self.eye_right.origin[0] + self.eye_right.pupil.x |
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y = self.eye_right.origin[1] + self.eye_right.pupil.y |
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return (x, y) |
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def horizontal_ratio(self): |
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"""Returns a number between 0.0 and 1.0 that indicates the |
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horizontal direction of the gaze. The extreme right is 0.0, |
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the center is 0.5 and the extreme left is 1.0 |
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""" |
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if self.pupils_located: |
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pupil_left = self.eye_left.pupil.x / (self.eye_left.center[0] * 2 - 10) |
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pupil_right = self.eye_right.pupil.x / (self.eye_right.center[0] * 2 - 10) |
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return (pupil_left + pupil_right) / 2 |
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def vertical_ratio(self): |
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"""Returns a number between 0.0 and 1.0 that indicates the |
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vertical direction of the gaze. The extreme top is 0.0, |
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the center is 0.5 and the extreme bottom is 1.0 |
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""" |
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if self.pupils_located: |
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pupil_left = self.eye_left.pupil.y / (self.eye_left.center[1] * 2 - 10) |
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pupil_right = self.eye_right.pupil.y / (self.eye_right.center[1] * 2 - 10) |
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return (pupil_left + pupil_right) / 2 |
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def is_right(self): |
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"""Returns true if the user is looking to the right""" |
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if self.pupils_located: |
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return self.horizontal_ratio() <= 0.35 |
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def is_left(self): |
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"""Returns true if the user is looking to the left""" |
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if self.pupils_located: |
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return self.horizontal_ratio() >= 0.65 |
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def is_center(self): |
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"""Returns true if the user is looking to the center""" |
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if self.pupils_located: |
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return self.is_right() is not True and self.is_left() is not True |
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def is_blinking(self): |
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"""Returns true if the user closes his eyes""" |
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if self.pupils_located: |
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blinking_ratio = (self.eye_left.blinking + self.eye_right.blinking) / 2 |
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return blinking_ratio > 3.8 |
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def annotated_frame(self): |
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"""Returns the main frame with pupils highlighted""" |
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frame = self.frame.copy() |
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if self.pupils_located: |
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color = (0, 255, 0) |
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x_left, y_left = self.pupil_left_coords() |
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x_right, y_right = self.pupil_right_coords() |
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cv2.line(frame, (x_left - 5, y_left), (x_left + 5, y_left), color) |
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cv2.line(frame, (x_left, y_left - 5), (x_left, y_left + 5), color) |
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cv2.line(frame, (x_right - 5, y_right), (x_right + 5, y_right), color) |
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cv2.line(frame, (x_right, y_right - 5), (x_right, y_right + 5), color) |
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return frame |
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